It is hard to determine the shape of drop handlebars online, because sellers photograph their products from useless angles (three-quarter view like Brucey’s above).....
you obviously can't tell
everything about a handlebar from a single photo but what you can tell from some (and is the reason why I very carefully chose that particular photo from the many hundreds of Cinelli Mod 65 that are available online) is that it very clearly shows the large radius transition from the tops to the ramps, and that it certainly won't result in a wrist clash when using the drops.
BTW to hear folks bang on about handlebar shapes, fitting into stems and Gawd knows what else one would suppose that quill stems and the bars that fit them had been around for about five minutes and thus far had all been made by folk that were wet behind the ears.
If you are daft enough to want the (IMHO) invariably ugly, often uncomfortable and (definitely) less durable modern style of handlebar, then don't expect them to fit in a randomly selected quill stem.
If you buy a stem and bars that come from the same manufacturer then they should be made to fit one another. A complication is that old Cinelli bars and stems (made prior to about 1990...? IDSTR the exact date of change...) were made with a 26.4mm clamp.
Apologies if this is b- obvious but when fitting bars to (say) a 1A stem then you should have the nosebolt on the inside of every bend as you feed the bars through; the stem is the shape it is (i.e. with a tapered profile when viewed from the front) so that will go round the bends nicely.
If you want to mix and match then you can do; shims to take up any gap there might be (I have run 26.0mm bars in a 26.4mm cinelli stem for yonks with a shim and it has been fine) and a little reaming to make stems that are too small fit bars they were never designed for.
If you do get a scuff on a reinforcing centre sleeve it is not the end of the world; unlike a single-walled bar where any marks or deformations are often fatal to the handlebar, a small scuff is usually harmless and can be covered with a computer mount or whatever. Because of the way the reinforcing centre sleeve works, you can even strip the anodising off and polish scratches out; it is extremely unlikely to cause the bars to break or anything.
BTW it is virtually certain that any handlebar with a reinforcing centre sleeve has been made by cold-forming the bends in the handlebar at a late stage in the manufacturing process. By contrast many modern single-walled bars are made by forming them when they are in the soft condition, then age-hardening them; cold setting or bending in a prang is far more likely to break such handlebars. Cold-set bars with centre sleeves can almost invariably be reset after a prang or modified in shape to suit a specific need (eg wider at the drops or something); not with complete impunity, but much more than you might imagine.
Speaking of imagining things, anyone who thinks they 'need' a bar over 42cm is probably imagining it; it is (IMHO) just a modern fashion to have wide bars. For many decades no-one made bars wider than 42cm and then they (grudgingly) started to make them 44cm. 46cm is just ridiculous (and might not be 46cm anyway; some manufacturers measure outside to outside and some C to C). If having wide bars were 'necessary for breathing properly' then TT bikes would be built with bars that wide too. I myself have much wider than average shoulders and I definitely go slower on wide bars than narrow ones simply because they force me to punch a bigger hole through the air.
All things being equal you should probably run more trail in the steering when you use wider bars (else you are more likely to be 'a twitchy wheel'), expect not to hold such a straight line when sprinting, not to be able to squeeze through gaps in a bunch so easily, and not to go as quickly when riding in the wind.
cheers
